While I make a point to support the small retailer, I hate dealing with small manufacturers/suppliers, unless as Silver Creek pointed out, they offer something unique, and even then I am hesitant.
There are a ton of bargain basement hook manufacturers for example these days, but I am picky about what hooks I use but once adopted when I need them I need them NOW, and not when the next slow boat from China arrives. For something like a vise, I need to know the manufacturer will be around for spare parts in 10 years. For rods, reels, waders etc. with warranties as mickmcco argues, I want to know they will be there to support that warranty.
The fly fishing industry if filled with small time operations becoming established brands. TFO and Echo for example are relatively new kids on the block but have made some very big inroads. Their product, however, was sufficient differentiated by price from the norm that they were able to create a new market in their own right. There is still some room at the bottom end of the price scale, but that is also where the lowest profits lie...
In a nutshell, my fly fishing dollars go overwhelminly to established companies, not because of name recognition, but because of the past history and anticipated longevity. YMMV.